Jet propulsion plant



y 1 F. A. M. HEPPNER 2,404,767

JET PROPULSION PLANT Filed April 28, 1943 23 .14 21 A? I I 22 27 27 .HI I 3/ 26 '2 11 i9 26 9 29 a0 IIVVEIVTOI? Patented July 23, i946 2,404,767 JET PROPULSION mm.

Fritz Albert Max Heppner,

land. assignor to Leamington Spa, Eng- Armstrong Siddeley Motors Limited, Coventry, Englan Application April 28, 1943, Serial No. 484,917

use in an aircraft, of the kind having counterrotatable parts, namely, inner rotors carryin some at least of the compressor and of the turbine blades, and an outer turbine shell carrying some at least oi the turbine blades. Preferably the compressor and turbine are of the t p According to the invention, the counter-rotatins outer turbine shell carries external air-screw blades.

A further feature of the invention consists in the air dealt with by the air-screw blades being passed into the jet-tor example, the plant'may have a stationary casing enclosing some at least of the air-screw blades and directing the air passed thereby into the jet.

The main purpose of the invention is to drive the rotatable air-screw blades at slow speed so as to keep the blades well below sound speed but at the same time to derive the power from a counter-rotating turbine which works under high relative speed. This arrangement provides the efiect of a gear between the turbine and the rotatable air-screw blades, without the complication of a mechanical 8681. I

In the accompanylnssheet o1 diagrammatic drawings; 7

Figure 1 is an elevation showing a simple arrangement according to the invention, with the stationary external casing or cowl omitted; and

Figure 2 is a similar view, but with the cowl showninsection.

In the construction shown resents an inner rotor of mounted upon it air-screw represents the outer by Figure 1, ll repthe plant having blades l2,; and I3 turbine shell of the plant having mounted upon it external air-screw blades It. The inner rotor ll carries some of the compressor blades and. also some oi the blades of the turbine, and in like manner the outer shell ,I'I carries some or the blades of the turbine. The plant may be of the kind disclosed in U. 8. Patent No. 2,360,130. The inner rotor H and outer shell II rotate in opposite directions and the provision oi the counter-rotating air-screw blades renders the plant suitable for use at lower speeds than it Jet-propulsion alone were relied upon, due to the fact that a higher expansion takes place in the turbine, so that the final iet speed is decreased.

In the construction of Fig. 2 there is an!!!- speed 01' the air relatively to the exhaust to constitute a Great Britain October 28, 1941 2 Claims. (01. 60-356) ternal casing l5 carrying brackets l1 and II fast with the ends of the casing l5 and serving to journal the inner rotor ll carrying the air-screw blades I2. Journalled on the rotor at is, 2| is a shell l3 carrying contra-rotating air-screw blades it within the casing l5. 2| represents counterrotating compressor blades and 22 counter-rotating turbine blades. 23 and 24 are brackets supporting the ends the shell I3 from the bearings I9 and 20. In this embodiment the air from the air-screw blades l4 mixes with the turbine propulsion Jet.

Each of the brackets 23, 24 is a spider having an inner hub .26 and arms 21 connecting the hub to the shell l3, air passing between the arms 21 of the bracket 23 to'enter the compressor, and the turbine exhaust passing between the arms 27 of the bracket 24.

In a similar way, each of the brackets II, II is a spider having an inner hub 29 and arms ll. between which air can pass, connecting the hubs with the casing l5.

3| indicates a fuel supply means for the air leaving the compressor and entering the turbine.

In this way the jet-propulsion oi the plant itself is increased by the external air being directed into the jet.

What I claim as my invention and desire to secure by Letters Patent of the United States is:

80 1. A jet-propulsion, internal-combustion turblne plant of the axial-flow type including a rotor, compressor an turbine blades carried thereby, a counter-rotating turbine shell radially outside of and enclosing said turbine blades, ad-

ditional turbine blades carried by said shell internally, said shell having an outlet to provide a Jet, external air-screw blades also carried by saidshell. and astationary casing enclosing said airscrew blades and 'having an outlet communicating with said first named outlet whereby the air dealt with by the air-screw blades'Joins the tut-- bine exhaust to constitute the propulsion Jet.

2. A Jet-propulsion, bine plant of the axial-flow type having an inner turbine rotor and a counter-rotating outer turbine shell, said shell having an outlet to provide a jet, external air-screw blades carried on said. shell, and a stationary casing enclosing said airscrew. blades and having an outlet communicating with the outlet 01' said shell for directing the air passed thereby to Join the turbine exhaust and constitute the propulsion iet.

mn'zsmanarmxmrnminternal-combustion tur- 

